The present invention relates to improvements in the field of laser imaging. More particularly, the invention is concerned with a sheet film cartridge for use in laser imaging having a motorized door which can be automatically operated by a computer.
Laser imaging apparatuses are well known in the art. These apparatuses are capable of producing on a photosensitive material two-dimensional images having resolutions of up to 8,000 dots per inch. One type of such apparatuses generally includes a laser scanning system for scanning a laser beam across a sheet film which is moved by a film transport mechanism. The laser scanning system typically comprises a laser source for generating a laser beam containing input information, a scan lens and a rotating mirror for reflecting the laser beam through the scan lens to produce a scanning beam with a constant linear velocity. The scan lens acts on the scanning beam to provide a focused beam spot that moves in a linear direction across the film, thereby providing a first dimension of the two-dimensional image on the film. Concurrently or alternately with the movement of the scanning beam, the film transport mechanism moves the film either continuously or in discrete steps to provide the other dimension of the desired two-dimensional image.
Laser imaging apparatuses of the above type require constant attention. Each sheet of film must be placed manually in the apparatus and removed by hand after each exposure. The exposed film is then brought to a film processor where, once again, it is fed manually. Both steps require a trained operator and a darkroom. For these reasons, laser imaging has been expensive and inconvenient. Apart from service bureaus only large corporations have had the resources to maintain an in-house laser imaging apparatus.
Sheet film packages and devices for loading sheet films into an image recording apparatus have already been proposed. For example, U.S. Pat. No. 4,799,591, issued on Jan. 24, 1989 to Tajima et al, describes a sheet film package comprising a tray for storing a stack of sheet films and a flexible cover member peelably attached to the tray in covering relation to a film access opening in the tray for shielding the sheet films in the tray from extraneous light. By inserting the cover member into a cover member peeling passage defined in the image recording apparatus, the cover member is peeled off the tray to open the film access opening. The films are then removed one by one from the tray and delivered to the recording section of the apparatus. However, once the cover member has been peeled off the tray, there is no protection of the unexposed films in the tray against low level repeated exposure to the radiation used in the apparatus for exposing the film removed from the tray. Moreover, the tray cannot be reused for unloading exposed films from the image recording apparatus.